Look for the Zero!
Before buying lawn fertilizer, check the bag for a set of three numbers showing the percentage of nitrogen, phosphorus and potassium. Buy a bag with a "0" in the middle.
Zero in the middle means phosphorus free and that means….
Zero pollution - Phosphorus is one of the leading causes of water pollution. Even if you live far from a water body, excess phosphorus from your lawn can wash off and pollute lakes and streams, harming fish and ruining boating and swimming. More than 100 water bodies in New York State cannot be used for drinking, fishing or swimming because they contain too much phosphorus.
Zero waste - Why pay for a chemical your lawn doesn't need? Generally, only newly established lawns or those with poor soil need phosphorus. Phosphorus applied to a lawn that doesn't need it won't be used and can cause water pollution.
Zero hassle - It's against the law to use phosphorus on lawns that don't need it. (New York State Environmental Conservation Law, article 17, title 21 and Agriculture and Markets Law § 146-g) Check local laws, too-some municipalities have stricter laws about selling and using lawn fertilizers.
An over-fertilized lawn can lead to a green lake! Excess phosphorus in waterbodies can cause algae overgrowth, including harmful algal blooms, with serious impacts to the environment and public health.